Method of making cockled paper



Dec. 26, 1967 C. R. RHORER METHOD OF MAKING COCKLED PAPER 2 Sheets-Sheetl Filed April 30,1964

Sheet, 2

. l 111 1 gi A Q (L C- R. RHORER METHOD OF MAKING COCKLED PAPER Dec. 26,1967 Filed April 30, 1964 2 Sheets United States Patent ABSTRACT OF THEDISCLOSURE A paper cockling apparatus including a rotating roll havingdepressions in its peripheral surface for holding water for transferonto separated spots of a paper web passing over the roll and dryingapparatus for drying the paper web as so wetted.

The invention relates to the manufacture of paper and, moreparticularly, to a method and apparatus for producing a paper having acockled finish.

Prior to my invention, cockle finished paper has generally been made offor separate from the papermaking machine. Previously manufactured,smooth finished, paper has been drawn from reels through a size bath;and the paper has then been air dried, such as by means of thewell-known festoon drier which supports the paper in the form of loopsbetween traveling spaced rods. The cockles in the paper, which are spotsthat are warped or bulged from the general plane of the sheet, areproduced on account of excessive and uneven shrinkage during drying.

It is an object of the present invention to provide an improved methodand apparatus for manufacturing cockled paper which does not require airdrying, such as by means of the festoon drier, and Which is, therefore,considerably more economical to use than prior methods and apparatus.

In brief, according to the invention, it is proposed that cocklefinished paper be produced by applying measured quantities of water ontoa paper Web in spots that are irregularly spaced, sized and shaped andthey drying the web, preferably by passing the web through aconventional drier drum section. Preferably, the web is drawn through asizing bath before the application of the water, and preferably thewater is applied in such irregular spots by means of a yieldable rollhaving an intaglio peripheral surface, the surface including irregularlyspaced, sized and shaped spots etched out of the roll surface forcarrying measured amounts of water within them for application onto theweb.

The invention consists of the novel methods and constructions to beherein-after described and claimed, for carrying out the above statedobjects, and such other objects, as will be apparent from the followingdescription of a preferred mode of practicing the invention, illustratedwith reference to the accompanying drawings, wherein:

'FIG. '1 is a fragmentary, diagrammatic, side elevational view of aportion of a papermaking machine incorporating Like characters ofreference designate like parts in the several views.

Referring in particular to FIG. 1, the cockling mechanism of theinvention may be seen to comprise a cylindrical roll which has aresilient peripheral surface and a which has a nip with a relativelynnyieldable cylindrical the apparatus of the invention for producingcockled paper and which includes a pair of nipped rolls, one having ayieldable intaglio surface;

FIG. 2 is an end view of the nipped rolls, together with a supportingframe;

FIG. 3 is a side view of the rolls and associated struc- 7 FIG. 5 is afragmentary, longitudinal, sectional view of the intaglio surfaced roll.

backup roll 11. The nipped rolls 10 and 11 are disposed in a papermakingmachine between a bank 112 of can driers and a second bank 13 of candriers. The drier bank 12 comprises a series of cylindrical, rotatable,steam heated drier drums, including the illustrated drums 12a, 12b and12c. The drier bank 13 comprises a series of cylindrical, steam heated,rotatable drums, including the illustrated drums 13a, 13b, 13c and 13g.

A horizontal size press 14 is located over the nipped rolls 10 and 11,and the size press comprises a pair of rolls 15 and '16 having a nipbetween them. A source of paper sizing, which is made up principally ofstarch and water, is connected to provide a pond 17 of the sizing in thenip between rolls 15 and 16.

A paper web W is carried by the drums 12a, 12b and 120. Suitable guiderolls are provided for the web W, and, as illustrated in FIG. 1, thesecomprise a guide roll 18 for directing the web W between the rolls 15and 16 and guide rolls 19 and 20 for receiving the web W from the rolls10 and '11 and for directing the web around the drier drum 13a.

The web W, after leaving the last can drier 13g, may be passed through acalender stack 21 to a winder 22. The calender stack 21 is ofconventional construction and, as shown, comprises a pair of steel rolls23 and 24 between which the paper Web W passes, and the winder 22 isalso of any conventional construction.

The roll 11 is suitably mounted so as tobe rotatable on a fixed axis.The roll 10 is rotatably mounted with respect to a fixed frame 25, and adoctor blade 26 is also mounted with respect to the frame 25 so that theblade 26 is in doctoring relation with respect to the peripheral surfaceof the roll 10. The blade 26 is carried by a blade holder 27 disposed ona pair of opposite shafts 28 and 29. The shafts '28 and 29 are rotatablymounted in bearings 30 which are fixed within bearing housings 31.

The bearing housings 31 are adjust-ably disposed in receiving cavities'32 provided in a fixed frame 3 3, and adjusting screws 34 and 35 holdthe bearing housings 31 in proper vertical positions within the cavities32.

Arms 36 are fixed onto the shafts 2'8 and 29, and these arms areconnected by means of links 37 with convention-a1 mechanism 38 foradjustably fixing the ends of the links with respect to the frame 25.The connections between the links 37 and the arm-s 36 are sufficientlyloose so as to permit longitudinal oscillation to a slight extent of theblade 26 and of shafts 28 and 29 in the bearings 30.

The blade 26 is oscillated 'by means of a motor '39 of conventionalconstruction which has a swinging oscillating arm 40 on its exterior. Abell crank 41 is pinned to the arm 40 at one end of the crank and has apin and slot connection 42 at its other end with the shaft 28.

A water pan 43 is disposed beneath the roll 10 and beneath the blade 26and blade holder 27. A water shower pipe 44 is fixed to the bottom ofthe blade holder 27 and has outlets for spraying water onto the surfaceof the roll 10 beneath the blade 26.

The various can driers 12-12c and l3a-13g in the banks 12 and 13 aredriven from any suitable source of power, and the rolls 10, 11, 15, 16,23 and 24 are also preferably driven. The roll 10 is driven from asuitable power source by means of a coupling 45.

The backup roll 11 has a relatively hard peripheral surface, and theroll 10 has a relatively soft peripheral surface. The surface of theroll may, for example, have a hardness of 120, Pusey & Jones Plastometer(Ms inch ball). The roll 10 is provided on its outer surface with aplurality of spaced discrete indentations 10a, which may, for example,have depths of about .006 inch. The peripheral surface of the roll 10 isotherwise cylindrical, so that the doctor blade 26 has a smooth runningcontact with the roll 10 as the roll turns. The roll 10, thus, may beconsidered to have an indented, intaglio, cylindrical surface.

The intaglio outer surface of the roll 10 may, of course, be formed in anumber of ways. One manner of forming that has been found successfulincludes the use of a plane zinc plate which is etched with the patternthat is intended to be provided on the surface of the roll 10. A papermat is applied onto the zinc plate after etching in order to make a moldfor molten rubber, and the molten rubber is then poured onto the zincplate and is set. A relatively thin molded rubber mat of about A; inchthickness, for example, is thus obtained from the zinc plate; and thisis applied and is caused to adhere by suitable gluing composition on theexterior surface of the roll 10 which is otherwise of relatively hardmaterial, such as hard rubber. A is apparent from FIG. 4, theindentations 10a in the yieldable surface roll 10 are, preferably, ofhaphazard shapes; however, they may, for example, be about A; inch widthand /2 inch length. The roll 10 may, for example, have an 18 inchdiameter, but its diameter is not critical. The roll 10 has a lengthslightly greater than the width of the web W, and may, for example, havea length of 120 inches with an 18 inch diameter, without excessivebending of the roll in operation (in this connection, it may be notedthat the roll 10 is illustrated in FIG. 4 as being of less length inrelation to its diameter than just given, and that the indentations 10aare shown larger with respect to roll diameter than has been mentionedabove, these variations being only for the purpose of betterillustration).

In operation, the web W passes over the driers of the bank 12 and is insubstantially dry condition. The web W then passes through thehorizontal size press 14, between the rolls 15 and 16 and through thesize pond 17, and is thus substantially wetted with size. After suchpassage through the size press it may, for example, consist of about 50percent moisture. The web W then passes between the rolls 10 and 11. Theintaglio roll 10 is preferably driven from the coupling 45 to have thesame peripheral speed as the linear speed of the web W, and during itsrotation the indentations 10a receive water from the pan 43 and from theshower 44. The pan 43 preferably maintained partially filled with waterso that the roll 10 is partially immersed in water as it turns throughthe pan 43. The doctor blade 26 doctors off substantially all of thewater on the portions of the peripheral surface of the roll 10 betweenand bounding the indentations 10a, and each of the indentations 10areceive and hold bodies of water which are limited in depth by thebottoms of the indentations and by the blade 26 passing across theindentations 10a and which are thus of substantially the same depth asthe indentations. The water held by the indentations 10a passes onto therelatively moist wetted web W from the horizontal size press 14 as theweb W passes between the rolls 10 and 11, and this action is accentuatedby the fact that the rolls 10 and 11 are under substantial pressure sothat distortion of the relatively yieldable surface of the roll 10 takesplace. A significant portion of the water, for example, about half ofthe water, contained by the indentations 10a, thus, transfers onto theweb W, although the indentations retain a small amount of water afterturning through the nip of the rolls 10 and 11. The effect of theintaglio roll, thus, is to add additional water onto areas of the web Wwhich pass over the haphazardly shaped and spaced indentations 10a andwhich areas are thus of haphazard size and shape; and the rest of theroll surface that has been doctored substantially free of water 4 doesnot provide any substantial additional wetting of the web.

The web W passes from the rolls 10 and 11 onto the driers of the drierbank 13, and these driers again dry the web so that it contains about 5to 10 percent moisture, which is that dryness that finished paper webordinarily has. The wetted spots of the web W that have passed over theindentations 10a dry later than do the other portions of the web W, andthis retardation of drying of the haphazardly spaced and shaped webportions has the effect of producing a relatively rough, uneven paperweb which is substantially the same as that produced by the loftingoperation previously mentioned.

The thickness of the doctor blade 26 or the pressure which it bears onthe surface of the intaglio roll 10 does not seem particularly critical;however, it has been found, for example, that a blued steel blade havinga thickness of .012 inch which protrudes behind its holder 27 by about 2inches is quite satisfactory. The shower 44 need not be used duringordinary operation of the intaglio surfaced roll 10, since theindentations 10a fill with water while passing through the pan 43; theshower 44, however, may be very useful in cleaning out the indentations10a. It is contemplated that sizing solutions may also be supplied tothe pan 43, if desired; and in this case, in particular, it is desirableto use the shower 44 for cleaning out the indentations 10a.

The intaglio surfaced roll 10, thus, advantageously applies additionalwater to the previously sized, moist web W in discrete areas which drylater than the other areas of the web as the web subsequently passesthrough the drier bank 13. The roll 10, thus, has the effect of printingwater onto the previously sized web W in discrete areas in meteredamounts, similar to the printing action of a rotogravure printing rollusing ink, thus slowing down the drying in those areas of the web inwhich the water is transferred from the indentations 10a. A cocklingeffect of the resultant paper web is thus obtained without the use ofexpensive lofting apparatus.

I wish it to be understood that the invention is not to be limited tothe specific constructions and methods as above described, except onlyinsofar as the claims may be so limited, as it will be understood tothose skilled in the art that changes may be made without departing fromthe principles of the invention. In this connection, it will be apparentthat the intaglio surfaced roll 10 may have a relatively hard surfaceinstead of a soft surface as mentioned above. With this change, the roll11 would be provided with a relatively soft surface instead of a hardsurface. With these modifications, the roll 11 will yield in thevicinity of the nip between the rolls 10 and 11, while there will besubstantially no yielding of the roll 10; and the soft surfaced roll 11will assure intimate contact of the paper with the water containingcells 10a in the roll 10 to provide substantially the same applicationof water to the haphazardly spaced areas of the web as previouslydescribed.

What is claimed is:

1 In a method of making cockled paper, the steps which comprise, runninga web of paper over the outer surface of a rotating roll that isprovided on its surface with spaced depressions, preliminarily fillingsaid depressions with water before application of the web to the roll sothat the water transfers onto the paper web from the depressions as theweb travels over the roll, and then drying the paper web.

2. In a method of making cockled paper, the steps which comprise,applying sizing onto a traveling web of paper, thereafter passing theweb of paper over the outer surface of a rotating roll that is providedon its outer surface with irregularly sized, spaced and shapeddepressions, preliminarily filling said dperessions with water beforethe roll surface contacts the web so that the water within thedepressions transfers onto the paper Web, and then drying the paper web.

References Cited UNITED STATES PATENTS Hampson 29121 X Arpin 162-112Yanes 101-170 Pearson 118262 Snowman 11738 MURRAY KATZ, PrimaryExaminer.

1. IN A METHOD OF MAKING COCKLED PAPER, THE STEPS WHICH COMPRISE,RUNNING A WEB OF PAPER OVER THE OUTER SURFACE OF A ROTATING ROLL THAT ISPROVIDED ON ITS SURFACE WITH SPACED DEPRESSIONS, PRELIMINARILY FILLINGSAID DEPRESSIONS WITH WATER BEFORE APPLICATION OF THE WEB SO THE